Lost all your car keys? How to get a new one

What should you do first?

Search once, properly, then call the places you have been: home, work, the last store and any lost and found. If the keys may have been stolen, or your house key was on the same ring, deal with that before the car.

• Retrace the day. Pockets, bags, the car seats through the window, the shopping cart corral, the gym locker.
• Call ahead. Stores, restaurants and offices often keep found keys at a front desk for a few days.
• Think about the ring. If your house key, a garage remote or anything with your address was on it, the home matters more than the car. Plan to rekey the house locks as well.
• Stolen? If a bag or keys were taken, report it to the police and keep the report number. Insurers often ask for it.

If the car is parked somewhere unsafe or in a lot that tows, tell the property manager what happened. Many will give you time once they know a key is on its way.

Can a new key be made without the original?

Yes. A replacement blade is cut from the car's key code or by decoding a door lock, and then the chip is programmed so the car's immobilizer accepts it.

Every car leaves the factory with a key code that describes the cuts on its key. Carmakers release key codes and security data to registered professionals, not to the public. In North America this goes through the National Automotive Service Task Force (NASTF), which credentials Vehicle Security Professionals and runs the Secure Data Release Model carmakers use. A locksmith who is registered there can request the code for your VIN after checking your ownership.

When a code is not available, a locksmith can often read the cuts from a door lock with a decoding tool and cut a key to match. High-security keys, the ones with a wavy groove down the middle of the blade, need a special cutting machine. A mobile locksmith carries one in the van.

Cutting is only half the job. On almost every car from the last couple of decades, a key that turns the ignition or sits near a push-start button also needs its chip programmed. Our guide on how car key programming works explains that part by key type.

What proof of ownership do you need?

Expect to show the registration or title and photo ID with a matching name. Careful locksmiths and dealers ask every time, because a key that starts the car is as good as the car itself.

• Papers inside the locked car? Common. The car is opened first and the papers are checked before any key is cut.
• Financed or leased? The lender may hold the title. Your registration and ID are usually enough.
• Name doesn't match? A spouse or parent named on the registration can confirm by phone and send a photo of their ID.
• Company car? A letter or email from the fleet manager or owner, plus your work ID.
• Lost the title too? The registration usually covers the key job. To replace the title itself, the Tennessee Department of Revenue's vehicle titling page explains how to get a duplicate title.

Anyone who offers to make a key without checking anything is a red flag. The same shortcut would let a stranger make a key to your car.

Where is the VIN, and why does it matter?

The 17-character VIN identifies your exact car, and it is how the right key, chip and key code are found. It is on the lower corner of the windshield on the driver's side, on the sticker inside the driver's door frame, and on your registration and insurance card.

Take a clear photo of it through the windshield. Send it when you ask for a quote. The year, make and model alone are not always enough: the same model can use two different keys in the same year, depending on trim or where it was built.

If you want to double-check the details, the NHTSA VIN decoder shows the year, make, model and other details for a VIN. It does not show key information, but it confirms that the VIN you copied is correct.

Locksmith, dealer or tow: which should you use?

A mobile locksmith comes to the car and makes the key there, so no tow is needed. A dealer can make a key for its own brand, but usually needs the car on its lot, which means a tow when no key is left.

When you compare, compare totals. A dealer quote plus a tow plus a second trip to collect the car is a different number from the dealer's key price alone. Ask each one for the total for your car, by text, before you decide.

Roadside plans usually can't make keys. They can tow the car to a dealer, which may make the dealer route simpler if the tow is covered.

What happens at the car?

The tech checks your papers, opens the car if needed, makes the key and programs it through the diagnostic port under the dashboard. Then everything is tested before you pay.

1. Proof. Registration or title and ID, checked against the VIN.
2. Entry. If the papers are inside, the door is opened first, the same way as a lockout.
3. The blade. Cut from the key code or decoded from a lock, then tested in the door.
4. Programming. A tool plugs into the diagnostic port under the dashboard. On some cars it needs a security PIN or an online login first.
5. Testing. Start the engine, lock and unlock with the buttons, open the trunk, and check the key turns in every lock.

Some cars need the ignition lock decoded instead of a door lock, and a few older models need the ignition taken apart. The tech tells you before anything is removed.

Do the lost keys still work?

On most chip-key cars, programming a key from scratch erases the old keys from the car's memory, so a lost key will not start the engine. The metal blade may still open the doors, which matters if the keys were stolen.

Ask the tech to confirm the old keys were erased; the programming tool shows how many keys the car now knows. If the keys were stolen with something showing where you park, ask about changing the door lock as well, so the old blade stops opening the car.

Why make two keys?

Because the hard part is starting from zero. Once one working key exists, a second is a much smaller job, and it means this never has to happen again as a full lost-key job.

With a spare at home, losing a key next time means using the spare and copying it, which is a short visit. Without one, you are back to proof, codes and programming from nothing. If the car allows it, some owners also add a phone key as a backup.

Does insurance or a warranty cover lost keys?

Sometimes. Some car insurance policies, roadside plans, extended warranties and key protection products cover key replacement, often with a deductible or a limit, so check your documents before you book.

• Ask whether they pay you back after the job, or need you to use their own provider.
• Keep the invoice. It should show the VIN, the type of key, and that the old keys were erased.
• If the keys were stolen, keep the police report number with the claim.

How do you avoid this next time?

Keep one spare at home and know where it is, and consider a tracker tag on the keyring. If your car supports a phone key, set it up while you still have a working key.

Keep the spare away from the car and away from the front door. Put the VIN and your registration photo somewhere you can find them on your phone. If your keyring holds a garage remote or a building fob, think about what someone could open with the whole ring, and split it if needed.